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authorTomi Valkeinen <tomi.valkeinen@ti.com>2011-11-08 03:16:13 -0700
committerPaul Walmsley <paul@pwsan.com>2011-11-08 03:16:13 -0700
commit13662dc5b177d68885695ef513dd4ae0e4d2a099 (patch)
treeeac0ee192bd0bf750368e82909dcec095e54800d /arch/arm/mach-omap2/display.c
parent3ce32676bb355420ceeda57b73dd84df0ff5ad6f (diff)
ARM: OMAP: HWMOD: Unify DSS resets for OMAPs
This patch adds a custom DSS reset function used on OMAPs from OMAP2 forward. The function doesn't actually do a reset, it only waits for the reset to complete. The reason for this is that on OMAP4 there is no possibility to do a SW reset, and on OMAP2/3 doing a SW reset for dss_core resets all the other DSS modules also, thus breaking the HWMOD model where every DSS module is handled independently. This fixes the problem with DSS reset on OMAP4, caused by the fact that because there's no SW reset for dss_core on OMAP4, the HWMOD framework doesn't try to reset dss_core and thus the DSS clocks were never enabled at the same time. This causes causes the HWMOD reset to fail for dss_dispc and dss_rfbi. The common reset function will also allow us to fix another problem in the future: before doing a reset we need to disable DSS outputs, which are in some cases enabled by the bootloader, as otherwise DSS HW seems to get more or less stuck, requiring a power reset to recover. Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com> [paul@pwsan.com: modified to build arch/arm/mach-omap2/display.o unconditionally to avoid an error when !CONFIG_OMAP2_DSS] Signed-off-by: Paul Walmsley <paul@pwsan.com>
Diffstat (limited to 'arch/arm/mach-omap2/display.c')
-rw-r--r--arch/arm/mach-omap2/display.c35
1 files changed, 35 insertions, 0 deletions
diff --git a/arch/arm/mach-omap2/display.c b/arch/arm/mach-omap2/display.c
index adb2756e242f..941b5459707f 100644
--- a/arch/arm/mach-omap2/display.c
+++ b/arch/arm/mach-omap2/display.c
@@ -27,6 +27,7 @@
#include <plat/omap_hwmod.h>
#include <plat/omap_device.h>
#include <plat/omap-pm.h>
+#include <plat/common.h>
#include "control.h"
@@ -172,3 +173,37 @@ int __init omap_display_init(struct omap_dss_board_info *board_data)
return r;
}
+
+#define MAX_MODULE_SOFTRESET_WAIT 10000
+int omap_dss_reset(struct omap_hwmod *oh)
+{
+ struct omap_hwmod_opt_clk *oc;
+ int c = 0;
+ int i, r;
+
+ if (!(oh->class->sysc->sysc_flags & SYSS_HAS_RESET_STATUS)) {
+ pr_err("dss_core: hwmod data doesn't contain reset data\n");
+ return -EINVAL;
+ }
+
+ for (i = oh->opt_clks_cnt, oc = oh->opt_clks; i > 0; i--, oc++)
+ if (oc->_clk)
+ clk_enable(oc->_clk);
+
+ omap_test_timeout((omap_hwmod_read(oh, oh->class->sysc->syss_offs)
+ & SYSS_RESETDONE_MASK),
+ MAX_MODULE_SOFTRESET_WAIT, c);
+
+ if (c == MAX_MODULE_SOFTRESET_WAIT)
+ pr_warning("dss_core: waiting for reset to finish failed\n");
+ else
+ pr_debug("dss_core: softreset done\n");
+
+ for (i = oh->opt_clks_cnt, oc = oh->opt_clks; i > 0; i--, oc++)
+ if (oc->_clk)
+ clk_disable(oc->_clk);
+
+ r = (c == MAX_MODULE_SOFTRESET_WAIT) ? -ETIMEDOUT : 0;
+
+ return r;
+}